SearcharxivSearch

arXiv subjects

Aofan Lin

Publications and source records attributed to Aofan Lin.

2 recordsLinked to original sources

Ultrafast electron vortex produced by a grating made of light

The generation of vortex matter waves carrying quantized orbital angular momentum is challenging and relies heavily on the material nanofabrication methods due to their extremely small de-Broglie wavelengths. Here, we introduce an all-optical method for generating an electron vortex by diffraction through a grating made of light. We realize the orbital angular momentum transfer between free electrons and photons by stimulated Compton scattering. The transferred angular momentum quantum number can be freely tuned. The method can be generalized to a broad range of charged particles, neutral atoms, and molecules of diverse masses. Our results open up novel opportunities for applications in free electron lasers and ultrafast electron microscopy by utilizing the orbital angular momentum degree of freedom of free electrons.

physics.atom-ph

Dynamical phase evolution of Coulomb-focused electrons in strong-field ionization probed by a standing light wave

We investigate the dynamical phase evolution of Coulomb-focused electrons in strong-field ionization. We diffract the electrons with an ultrashort standing light wave to track their time-dependent phase. Our findings show that low-energy electrons exhibit a unique chromosome-shaped diffraction pattern, distinct from higher-energy electrons. Our numerical model quantitatively reproduces the experimental results, confirming this pattern maps the electron's time-dependent phase evolution as it escapes from a Coulomb potential. Our pulsed diffraction grating technique offers a new way to sense an electron's quantum phase without interfering its release mechanism.

physics.atom-ph